Abstract: The dynamic soft reduction technology for 360 mm×450 mm bloom caster and its application results at PISCO (Panzhihua Iron & Steel Co.) were presented.Experiment for contrasting process with or without soft reduction for bloom was investigated, in order to analyze the influence of the soft reduction on internal quality of bloom, such as center looseness and central segregation.The operation shows that after applying the soft reduction to bloom of alloy steel, the ratio of center looseness which is ≤ 1.0 increases from 66.67% to 85.71%, central segregation which is ≤ 1.0 is increases from 94.44% to 100%, central shrinkage cavity which is free increases from 88.89% to 96.42%, and central segregation index of carbon decreases from mean value of 1.15 to 1.05.These results have provided important technology supports for PISCO to optimize the steel product structure, and to improve the production of high quality, property, and value added products.